Here is another  idea

I am assuming here the blade would be of ferrous material
Mount a permanent magnet near one end of the tip of the blade
Mount a pickup coil so when the one end of the blade is closest to the 
magnet and the blade is in one of it's extreme positions (19 or 32 as far as 
i recall) it is over the coil

The pickup coil ac voltage will be proportional to the angle
magnet and coil could be behind an aluminium or non magnetic stainless steel 
shield or similar

Peter

----- Original Message ----- 
From: "Jinx" <joecolquitt@clear.net.nz>
To: "Microcontroller discussion list - Public." <piclist@mit.edu>
Sent: Wednesday, November 17, 2004 6:45 PM
Subject: Re: [PIC] Turbine blade... was problems


> Thanks for suggestions so far. I've not yet clapped eyes on
> the actual mechanism but I think it was fairly well described
>
> I probably will be writing s/w to control the angle at some
> stage but, until I can examine the turbine personally, how I'll
> do it is speculative
>
> Strobing or light reflection sounds like a goer, I was never keen
> on electronics inside the shaft housing. Presumably (hopefully !!)
> the turbine is of solid construction and the blades will be stable.
>
> One possible problem is where the measurement will have to
> take place. On the bench there are several options, but
> practicalities in the field may force an internal solution. Yuck.
> But results from bench-testing could be taken out in the field
> for reference (fingers crossed)
>
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